Telephone-exchange system.



H. G. WEBSTER. TELEPHONE EXCHANGE SYSTEM.

APPLIGATION FILED JAN. 13, 1906.

Patented Aug. 10, 1909.

2 SHEETS-BHEET 1.

Auansw. Jim 06. mom-mm WW 1 c.

H. G. WEBSTER. TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED JAN. 13, 1906.

Patented Aug. 10, 1909.

2 EHEETB-iKHEET'z.

I UNITED PATENTQFEIEGE.

HARRY e. WEBSTER, OF-OHIOAGO, ILLINOIS, ASSIGNQR TO MILO e. KELWG 0F OHTGAGO,

ILLINOIS.

' mmmmom-exeamme svs mu.

Specification of Letters Patent.

me e Aug. .10,

Application fi,1ed1am1ery 18, 19.06. s u ivne. 295,985.

multiple sw'i tdlmboamdi to the two wvsmesof a connected telephone line with the Becompenying advantages of common better-y vat.

the neutral ofliee, .a suitable :binsy test the usual line and supervisory signals: 1311 systerns of this type, it :is d'esireib'le itokeep :thie twlking-cireuit tree mom separable 'olontaets, 110 employ simplee p'zeratus and'to obtain a posifiye azotion 014 t parts through e-Wide drange "o'f 'soonditions met-in: install:ing the'= sys utema lit llS'&l SO" of advantage to whawre the tIIaiHSmlSSi OIl-CUI'IBHTJ swppl-iedin 'bnidgenf .fihe 00rd eimeuit, "to have normallyge; {ii-meet: :eariih oonmetion-on'that line limb'assoeiated: with the testing xeemih-el, andi to have the i line limlbs fnee fa'rom lewrres istwnoeearth (sonnet:- tions at the -exeh=a;r 1ge when oa'llingie swbscribe 1' .:.-vv I, rfllhea o'bjeet' efizth'e present :imuviention to pmovidea novel ongeanizmtion oi ioii ouios :aarrl ;a.;p. Ema-1111s fomaecomfilishing fihese' ends. heuvmions'zfeadiures QfZtIQWI BIty flh'eir iaioeompeinyingz advantages; wdil. more fully ;:-'E:ig1i-re'i ?1 illustrates. ttiegrammnaltieazliy -& time wife :sgysiiemi eons twisted: tin smcnnd with zfihew esent; iinyntiomnshewigngea e01 pen sihaell \afiut'riihe eoneazofi thEsWtjQE re egy :fornendering itjire samemonefildifotziwe; 2. lust-mates mpontibnofiw'snnileflsystein in which the icnto'fii neln yeis enendmeelmonillnstmtes qi iagniemsnubieally lanothom: twao Quit; to ethemwith anin elependent seumelim" s l'lipplgiwgatnwnshlissibmnurmtgissyeti;

eleevmeeueemenbm o :41

non indnetiv'e bythe use of twin l windings included in the telephone: line limbs-. R fenring to F'g. 1, A and? B diesigimaoe sn'bsteti ons whieh'ene'i connected both-e eentqral ofifiioeU by suitable telephone lines. willhe equipment "at substation A, may'ibe' ef any preferred type,- i's-liere she-Wm es ieom- .prising a :eLell-ebell it in serlies with a condenser 21, inpermanent bridge oi the telephone. line limbs 3 -4; Aseemidrnonmally .o penxbri dge, 'incluidingthe tizensmiitter 5 endt esreeei-irer 6, is closed at the contact 57 :by the :switehhook 8 whenever "the receiver is. removed -1henefrom. At the con anal oflieei,-t:he:-.line limbs 3 and QESLFG 1201111 eoted' to -the distributing-frame F, from .Wh-ieh they. eneweontimaed by the extension eoncluotoris-m neto athe oon- 't-or is permanently e'olnnmetei'l' at the point J2 by a. branch :14, fineludingmhe windingwia f ljlhe {extension .0 ontlnetorm: is seonneated by n eonduetor 1 7 ,4130 a; fixed content 18 am the-zone offca'elzay, which oolvivwperates with theamowihle :l u ded the mind- I 2e, eel-meeting I the fixerlwbon teetsz of'ithe line emit l :Gttfl-iflfii; meleges a respeotimaly, and: ithe snolmbleigooniiact 'ef-mhezou trafi ireley which is eonneetedebg ew ieaondueto'r 28%?) @eaemeveee aorifiabtxslfll w Tillie ieq'iih' pmmiti Lam ,sthe eonn'eetionsiibhus fervdeseribed wiehwefiemnaerko swhsmtionwzi ieme apnaet'ieaillyduplieeoed in eoflneetiifine-svieh substation}, and! the eeireb oneihggpamtsemize im-idipatei by smilampi'imelilsrhiinaetenst The interconnecting meansiefitlimeanbml ukukeondensezsififixam ammieiintermseebe we inBtenm ETeImMdiHusQ-MMH dbuiblerwfe I'h-fthe ,titip erationot the asparty at self to these 'specifi c" resistances.

the supervisory signals. The relay 41, which. is associated with the answering end of the cord circuit, has one winding 42 included.

in a branch 43 between. the strand 31 and a conductor 4.4, which is permanently (3011?.

nected by a conductor 45 to the grounded side of the battery. The other Winding 46 is included in a branch 47 between the other strand 36 and a conductor 48, which is permanently connected by a conductor 49 to the live poleof the battery 16. The relay contacts 50, 51 and'5'2 control a branch 53 between the conductors 44 and 48, which includes the signal lamp 54. This branch is normally 6 'en at the contacts 50' and '51 and may be c os e'd by the engagement of these contacts, due to a certain energization of: the relay magnet; and. again broken between the contacts 51' and 52 by'a further energizati'on of the relay magnett' A second supervisory relay 55--comprises the winding 56 included in a branch '57 between the strand 32 and the conductor 44, and the winding 58 included in: a branch 59 between the conductor 48 and the strand 37. Its contacts 60, 61 and 62 control a bridge 63 between the conductors 44 and 48, to cause'the display and effac'ement o f the supervisory-lamp 64 in the same manner as that heretofore described' in connection: With therelay 41.

The windings .of the supervisory relays are of relativly ldw, resistance as compared with that of the line relay 15; for instance, the formermay' have a resistance of one hundre d ohms each, andthe latter five hundred ohmsj However, I do not Wish to limit my- The usual listening-key 6566 is employed toclose a bridge; between the contacts 67 and 68,

which includes the operators receiver 69,- a condenser 7 0 and the-secondary winding of an induction c0il'7 IIheoperato'rs trans- =rnitter -72 is includedin 'a' local circuit with the primary ofthe iinductio-n' coil 7 1. and a battery 73o The bridge is connected-at the ointfl to the grounded side of the battery a conductor '73 through an irnped ance 78 5 The ringing+k ey E 7 i normally en gages the contacts 76' and a to maintain-the continuityof the strands 32 and ;3 7;,--bu t 1na'y be depressed zintoi engaigenient withi thecoriitactsi and '79 to 'closeia bridge80 through "the lamp 81=jand-the callinggenerator 82 whichpgreferably; has one of its poles substation I A', 'desi-ringi a to converse; .with a party at substation B; "removes: his receiver '6'-so"as?-tr elose the bridge including are transniitter Sand receiverfi; contaetv and switeh nice the ap ears poles ctthc' bait eilrtensfionfebnductois n; 1 to "the li ne 'iimbis '3 and 4 the closing"- of the bridge at the Sue 'sultzover theistran station will com' lete-a circuit through the its display,-as asignal to the operator that a connection is desired. Upon observing this signal the operator will insert the answering plug 29 into the answering jack of the line 84 and depress the listening-key 6566 to connect her receiver 69 in circuit with the substation to learn the wishes of the calling party. The insertion of the plug 29 into" the jack will complete a circuit throu' h the Winding of the cut-off relay '13 as-fo lows: from the live pole of the battery 16 through'the conductor 14, extension conductor m including the winding of the cut-off relay -1 8', jack contact 10, tip contact 30, strand 3-1, branch 43 including the winding 42.0f the supervisory relay 41, conductors 4.4and 45 to the grounded'side-of the battery. The closing of this circuit will energize the cut-off relay sufficiently to attract its contacts 19 and 27 to disconnect the line limb 3 and its extension conductor n from ground and to break the bridge including the call signaLlaInp 21 thus extinguishing it and; removing its control from the party at the substation. At the time the plug 29 is first inserted in the jaclqa circuit will be completed from the active pole of. the battery 16- through the conductorsi lS), and 48,:the branch 47 including the-windin =46 of'the supervisory relay 41,"strand 36; sieve contact 35, jack contact and conductor 20120 the groundedsideof the battery. Thiscircuit will be only momentary, since the energization of: the cut-0H relay will break-it at the-contacts "18- 19.

When this occurs, the circuit will be completed from the .jiackcontacti 9 to the grounded side of the batter-yr; :Wiay of the'extension conductor has ilimb 32,-, the r transmitter and receiver bridge atthe substation line 1 0 tip 30strand 31, conduct0ri43 including thev Winding; 42.: of the:v supervisory relayii 4i and conductors s 44 fand 45; f 1 These circuits threugh: tlie' windings-of the supervisory relimb 4, eXtension-conductor m,- jack contact lay 41 will energize it suflicintly to'draw the contact 551 out ct iengagement with the: contact :52 andmth'erehy maintain the signal lamp 5'4 i'dark:- 1 :Upon learningthat thecalling" party desires a connection with substation "B the. operator willitouch 1 the tip 3-3? cf the callingzp ug' g le to ones ofthe jackets- --taets 3 tddeterinine-wliether the? line: is busy or idle. Ifthezline 'i-s;busy;.- there beta of ground; and as soon the tip contact? is i touched againsti v and. is normally closed at thewcontacts 1 116".. 1"1=7 of the associated relay 1:1 8,tand

. :1 36 and 1.37 is I providedfori closing. a; bridge of, the relay 131 1 5 r normally openat the contacts 1 19'::120 ;of the associated relay121.

relay- 118- is includedin a branch .-122 between The winding of. the

the cord strand -10'9 and the liverconductor 1.1 6, While the winding of .ther'elay 1121is included in the branch '123between the strand 2104 and ground. "A su e-rvisory lamp 124,

associated with the call i circuit, is similarly included; in a branch 1.25 extending through the contacts 126and127 ng .end :of they cord ofthe. relay 128 and-the contacts1-29 and130 The windingsof these relays are similarly included onrthez one; hand by abranch 132 between thelive conductor 116 and.- -.the strand I 110, and won the iot-her i hand bya conductor 133-betwleen the strand #105 and ground The usual: -listeni'ngekey 134. 135-,- cooperating with the contacts between the strands .1 0,51 and .110 including the-uoperators receiver 138; the condenser 139 andthe. secondary of-Zan induction coil 140 .The op'e'rato'rs transmitter 141-isineluded -in ;a, local: circuit: with the primary Winding ot the 1 induction coil ,:140.;and;:the .battery.:142: The ringing=genefator 143,

having .one of its poles grounded. at 144 has its active pole connected throughail'a111p-1345 and conductors 146 to the contacts L457 and 1 1.48,-:which cooperate -Wlth the 1 levers 1.49

with the levers- 1 52 and the listening-keysu i 1- v f IIIFtlIGEOPBTatIOH o'fthe: system diseloseddn this figure iaeparty at. eithersubstation Af or Al; desiring .to? co'nversewith "a part-ymat and 150 :of the ringing-keys -149.'151 =an'd 150"1:52,respectively. Y I

of .the generator is connectedbyconductors T e a grounded pole .153 to :contacts- 1 54; and 1 55;Which cooperate 15.1 respectively; iof

either isuhstatiod B .or: 13?, upon remoying 1' his; recei rier :froni its nhook, :closes a: metallic --.cirouit-= betweene the telephone liiiibs 3 and 4 -45.

;ciently,to display-the callisigna'l 215; as:a-s ig- .nal to: the operator that he: desires :c'onnec- .tion; I i This .-circilit;.extendsffrcimithetlixfieapole 501 the battery ;.1 v '50,

widely.

and1;thereby energizesuathe relay 15 suffithrough the conductor 14, conductor 4m, dine %limbs 1' and conductors m relay: contacts '96; $9 1 valid 95, ito Upon. observing this signal; :the: op-

ground;-

iajlirl tpthethattety '1 0:1 ,ctlircnglr'cenof;;thez relay 118:, astrand 199', plugisleeve I jack-1 1' Asaprezviouslyi 1n close-a ;.circuit; from g the: live .pole :of the; .bat-

(closed? :froi'n 108, sack contact: 9 cut-Jeff relay contacts w-+981, conductors 9.9and 17 and cut-off relayieontacts 96, 94 and 95,:toround; 'The closing of theformer circuit w energize the movable contacts 94 and 97, thus opening the latter I circuit at the contacts 94+r96; removing th'enormal ground from:the exten- Fsion ehnd iictor n' ofithe linelimh 3 @andbre-aking: the branch including the: call signal: lampc.

'- 21,- thusremov-ing its control from the calling subscriber." .:l..he energizationof the cut-"01f relay 93- will also-remove the 'shortscireuit through the conductor 99 "around the :relay w rinding 91$ Thus after theoperation ofthea, cut off relay .93, the circuit from the battery @1011 i's continued from the: jack contact; 9, through the extension;conductor'n including thewinding 91 of thecut-oft relay, :line limb 3;,-tl1e5 closed bridge at the substati'on, line limhg; extension conductor in including the Winding. 92; of the cut-off relay, to jack eontact 10:, thence by Way or the .tip I contact 1 03, strand 104 and conductor 123, to ground. The resulting energization. of. the relay-93, :due to the excess I of current .in one Winding rover the other;.is suficient to+retain thecon- -tacts-94 and 97 in their attracted :positions. The. current flow in the supervisoryrelays 1 18 and 1'21 is alsosuflicient to attracttheir contacts 0116* and 119 respectiyelmz thus i breaking the'grounded branch 115 atone point and closing-it at-another; thereby preventing the lighting of the supervisory lamp 1:14;; (By depressing theliStening-Jkey 1 34*. 135, the :operator may :elose 1 a" circuit through her :receiver -188 and1obtainsthe wishes ofithe-calL ing .party: i Upon learning: that connection is desired "with "the;-line 3 r4 she will then; in

order to determine the busy or idle:condition Of-the iline; touch the 131111106 of the; calling- :plug 107 against the Contact 9 of Tone of the rjaekst-cbrrn ected Withsaid line; and if' the said line -.is-: busy the iiotential= onlthe contact :9 will Ecause a: flow of current from the ti *con- 106;:0yenthe strand 1:05.:arid con uctor 1 33;; to ground; ziwhich-" be. sufficient: to -:1n'odifiy -the schargelson th'e condenser .1s39.+i.re-

* csulting. zfrom-the initial closing of' the. listen- 1 ihge'k'ey 3i5+i+toicause a ftclickt her receiver 1325, thus indicating? the. busy nonditipn of %the line; Ifx-the line isitonnd to a be idle; :she :Wilt thenainser-t the lug 10% j intolthe dlieatedithis will :tery; '16 .ov(iii-tile- .cond ctor 4i through: the 92'! gofethe :eu t -oft' relay .110? the tip wstran'd iOf the :corde cinc hence to ground ithroughsithe condiietqr w The-closing' of .:-this circuit will sufficientlly @131 to clesethe1contacts1129an di 1a3fivto; coinlete the-grioundeii-lbranehvl25-;ithereby causthe *displaysot the signal dampi 51:24:; At -thesame timenas'. eviouslytindioatedgi 'sciiit. will be; comp etedlfrom theilive polenof ze tthealelay limit? the battery I 01', lower the sleeve strand at the motdeimuit, through the shontrcibcuitihg conductor 89 and the; conductor; 17 of relay eontacts Q65, 94:.4M1il95fltii ground. :'ll1e result, of the completion of these circuits will be the actuation of the cut-off relay contacts to remove the call signal 214'from the. control of the subscribers at'substa/tions B and B, to remcveithe normal greundlfrorn the extension conductor n ottheline limba, there by interrupting, the cineuit, from the batter; 1 1:91,]an'd to remove the-shortcirouit throng theconduotor 99, thereby establishing the circuitafro'm the sleeve strand'oizthe'oord oir- 'cuit through the extension conductor. l n including the Winding 91 .of the cut-ofirelay fi3, over the line limb 3. to the open bridges at the substation, thence by way of the line limb :4, extension conductor including the: cut-oil relay Winding 92, jack contact 1-0, through the tip strand of the cord circuitiancl the conductor-133, to: ground. After establishi'ng theconnection-With the telephoneline 3-4, if conversation is desired with the party, at substation B, the operator depresses" the ringing-key 149151, thereby connecting the line limb 3 to ground and sending calling current, over the line limb 4, through the call-bell 11 at the substation B". If, on: the other hand,- conversation is desired with the party at substation Bi, the ;.0pera.tor

depresses the ringing-key r 152 150,: thus connecting the line limbef-to {ground and sending ringing current over the line limb 3 through the callbell l sit-substation 13 to ground, As soon as the called party removes his, receiver, he will close, thenormally open bridge through his transmitter andreeeiver'end thereby complete vthe normally open circuit through the windings ofi the. supervisory: relays 128 and 181, previouslytraced. 'l=he'fcompletionwof this circuit will energize the relay 1128 sufficiently to separate the eontaets' 126 12 7 and thereby break the grounded branch 125 through thesu ervisory Iamp124-,,to;extin it. ,With-t egparties thus 2 connected, 1e -super vls'ory lamps 13A and ll 24. will remain dark and. continue in this.

condition until either fiartyshangs up this receiver, at which timet eoo rrespondingdami isliglrterh The 'lightingef-both bfj-these lamps is-arsigne l toai'iheuoperator to adisoonmect-itheaiparti-es-r i we'll knownmeans .isprovided tori xenderlng relays 93 and 93! nonsinduotiwe. In this inst-anew this-.iseaecomnlished the telephone line limb side by sideruponthe were of the relay magnet l i :I-n carrying out my: -.inirention, ehviousl 1 many other means for renderingltheieut-e relays non-inductive might be employed,

- towel-strand link'eirouit fan tion to said :line-limbs,=,:meens ionho ding-h0g and many other, alteijatiensvfln mmfirfimtiers might be -m Ml9-ifl1l the sppaficimatte herein disclosed, without departmg fro {idle spinitand'eco e qf my invention-r IrLt' re fore, do. not-wish tobe limited: to th ywifi matter al-3010586 but i t e ireryby th terms of the aep ended elaims, all sueh filteretions and modificatiens. .iFhneughout th phone line, tor-include not=only-theflteleeh n e l ne prover which; terminates 1 earth-e 5 distributing board butr also the I QE'QBRSIODS thereof from-said hr iarrd-v towthe con-mete jacks land the seeree ,ot current;

What I claim as new; and teatime-secure r by, Letters Patent oi the United-,fitates, -is- 1, A two-Wire telephonetsystem nomprising a telephonewline;.entendinginwtufo limbs from a substation to a vcentral office 1a two-strand linl ;c.-ir,cuit1 for-v making oonneetion tosaidline limbs-,. means. for holding conversation' over 1 the connected lineand linkcircuitgean eleetrome nethan hgran energizing windingin the tzfiking circnit when eonnection is made forconversation; andmeans.

for making and breaking a, short cireuit about said magnet winding 2. A tw-oswi-re telephone system scornprising a telephone. line: extending intw'o limbs from asubstation, to. a central office a two-strand link-eircuit {or making connection to said linelimbs, means. for holding eonvcrsation over; the connected line-and linkcircuit, an electromagnet havhig an energizing- Windiingin' one. limbofthe telephone;

and included-in the talking circuit when ednv nection is made for; conversation; andn jeans for making and breaking a short eircuit *about saidmagnet Winding.

v 3; .A "twoewjire telephone. system rising a telephone line extending intwo imbs from a substation 'to-,a.-central efiiee, a

twoestrand linkwircuit tort-making {rename tion tosaid line limbs,- Imeans ferzholding comers ation over; the connected? line.: and: :lrliiiki cirouit, 1 an: electnoinegflet having; an energizing winding the talkingeeireuit swhen 'oonnection is made. 1 foraconvessafiieil,

means for makingwanid breaking ats'l'iorteeii euit about eaid magnet winding and; means fer v furnis ;-treinsmifssionseurrdnt tQv'l' h connected, t epthone line-even the link-ear- Al A. ftwo wlire ssyistein grising at l phone: Jinet-extendin, 1 in tw limbs from a substation to a centra oflioe,,a

enmesversation ojver the connected linewndvlinkebnnectio is made; tor: eonnersatio l means iforand 94; shortrelmmt about said magnet winding, and means for 5 prising a telephone line eicten two str and 5 link eireuit for: making oonneo- "tion 'to= sai'd-lh1e limbs, means for holding conversation over' the' eonneetedline and 10- link-circuit; an electromagnet having an -en-.

ei' gizing' Winding in the" talking circuit" when connection is made for -=oonversation,- and means actuated by said elect-roma'gnet to mterrupt a normal short' eircuit about-said elect-romagnetwin'ding;

6. At two wirtelephone system- 'oom-' prising' atelephonejline extendin in two imbs from a substation to a :centra office a two-strand flink-oireuit for making connection to "said-line -limbs,=-=means for holdingconversation over the= link-elroult; an'eleotromagnet having an en ergizing winding in one limb of the telephone -line,-an"dme'ans' actuated by said eleetromag- '25 nettointerrupta normalshort-oirouit about said eleotrom-agnet Winding 7 A itWO-WiI'G telephone system eomprising a" telephone line extending in two imbs from a'substation-to a central oflioe, a

two strand -link-cirouit for-making oonneo- 'tion to said-line limbs, means for holding conversation over the connected line 4 and link-Circuit; 1 a e'all signal normally uncle'nthe' control of the subscriber; aneleetrornagnet;

hating; an e'nergi zin g Winding ingthefta'lking "circuit when'oonneotion is made for eonver sat-ion;- means for making and bre'aking'a =short-oi'r euit about said magnet Winding, and

means aotu ated' by said 'eleo-tromagnet to de- 40' stroy" the substation control of said call sig two-Wiretelephone system cornprising 'a telephone line extending 'intwo "m -b's from a substation to a Central offiee, a

tion-gt'o rsaid 'line limbs 7 means for" holdin eonversation -oV' "r the reenn'eetem lme and iin k ei reuitg' a mu {nalnormally under the.

I v7 J -oo'ntro lmf thes bseriber',' aneleotromagnet 0 -havingan energizin Bataan-st n'dlink-oirotit ffonniaiking eomree-iv versation; means operative upon-the eonneoin the talking -e'ircu-it when eonneetion -is ma'de- "o inve'rsationg and means aetuated by -"sa1d e leotro magnet to interrupt a normal short eitoiait dv 'electmmagnet winding and to -deflFtwo -wire telephone system oomsing telephone line extendingin two '-'imbs=from substation to a oentraloifioeya said li'ne "limbs; means 5 fan holding cenversatio a the ephneeted line and *Jinkeeirtuit; almormally undemhe anti-sign eont'rol o'f jthe subs'er-ibe r, n-eleetremagnet liavin an 'ene'r" 'i'zing' {winding "in one limb of the'te ephon'e' ine; and rneans aetuatdby said ele'etro'magnet to interrupt a n'or'mal short-circuit about said ele'etiolnagnet Wind- 'saideallsignaili a 10. A two-wire telephone system comprising a telephone line-'extendin in'two imbs from 'a substation to a 'eentra' office, a

jtio'n to said line limbs; means for holding conversation over the "GREGG/bed line and "link 'e'ircuit 5 an e'l'eotromagnet Having an energizing Winding-in the talking eiroui t when operative upon the connection of said linkoiro-uit to said line to"energize' 'saidelectromagnet, and means actuated b magnet 1 to interrupt normal short ei'reuit eonneeted: line and about-saidel eetroin agnet winding.

11. A tWO-Wi-TE telephone system oomprising a telephone line extending in two imbs froma substation toa oent-ral oflio'e, a two-strand:link oircuit for making connection 'to said line limbs, 'mea-ns for holding conversation over the connected line-and link-circuit, an eleotromagnet having an energizing Winding in one limb of t'he telephone of said link-"c1 rouit to said 'lineto energize said eleotroniagnet, and means actuated by *said leotromagnet to interrupt anormal heftcircuit aboutsaid =e1eetroinagnetWindf -A two-wire telephone system oom- 'nsinga telephone line extending in-"two limbs fromasubstation-to a central ofli'e'e, a; t Wo-st-ra'nd' link-circuit for making eonne 0- j tion' to said line; =1imhs means for :helding conversationo-verthe eomieeted linei and dink-circuit; a call-signal normally under the control I of the su'bsoriber, an eleotromagnet havingan energizing winding I in the, talking oireuit' when connection is tion of said link-cirtzuittia said line to ener- '--gize said electromagnety and means" actuated ing'and to destroy thefls u hstatioh' eont-rol of connection-is made for-conversation; means line, Ine'ansoperatine' upon the connection.

h the two-Wire! telephone system .i (ioniing twlo -twostrand link oireu'it for making 'eonneesaid eleotfo- 'made for con by said eleetr'omagnet toi'interrupfi a normal shoutoimcuit aibmit sandmlbet-remgnet wiundand to destroy this swlnstmtien con-trot ofi sand cahlz-signflah 1-4. A -tw0wwire telephone system comb rising as tel'cpflnmle kins exebe in two bs from m smbstartima to e eeutfi ofiiee, a; two strand: ld' nk ei-rcuit for. marking eonnection to said line limbs, means. Eon: hold conversmtionoxrer the connected mu kimkoincuit, an, eteetrcmegnet hearing an em ergiming winding in: each side otthe' talking circuit when connect-ion is; for convers setion, mews; flour making 811101 weak ng a short-circuit about one of said magnet windsin I5 rising e telephone line'extendin in two: Embsfinom-m substation to) a cent]: ofice, 2 two-stranct Enlscircnit for makin --eonnection to saidlimbs, mem sfior 1B0 ing con-. Yersaition ower the connected and Linkcircuit, an electromagnet having an tanner-.-

twmstrsnxi Link-circuit for making cennee.

tion tosnici: lime means ton; eonversation. over the connected l me and circuit, amelectromaig net halving sin-energiewinding each side the: tar-liking circui't when connection is made fie: cmvensetion, and means actuated by said e1ectro-.

magnet to interrupt a normai short-circuit about" one oi-said magnetwil dings 117.. A "trm wire telephone system coma. telephem time extending in two. miles from at substation to a cent: oflice; a two-strand link-circuit for connce tion to said Jgine limbs, for

conversation. over the connected am-1 link-circuit, ehecmep I ;xetteaming an energiz ng wmidmg 151; each. but the'teleconversation emertlmeceinmeeted ime. and

111w when-connection is; W for -fi mnd mmiwmak md I: ei liitfah-out one id megnetmimimgss 3 M I tworwire t-eiephone system com E 19 A twehnine telephone system com- Erismg: a telephone extending in two 'mbsfmm a subsliationto m-cerntrak ofioe, a iwo stmmi limkeciineuit making commotion to said. fine limbs; means fionholad-img con- -versetion oven-the commeotedline and linkcircuit, a (ificlilhsigfifll llflIWAi-(IQY' mitten-tine con- 2 tract of the srubscriben. an: electromagnct hawi sn-energizing winding inecoli l'irmb cit time te phone line when connection is made. florcomversetion, means; for making and breakm ShflbihCiIZGlhit altommoner ofi'said mngmset windings, and means. arctimtert by said; electlzomaglmet to destroythe substation control oi solidi" celli signarL 20; A two-wire telephonesystem-comhmbs from Eb so]: station to a central office, a ilVOrSbIBiBdl link-circuit E01? making connee 'tion to; said limbs, means tor holding conversaztio-n over the connectect line and mlink cimeuit, a; celksignalnormaflhy under the control ot the suhscriber, an e-lectnomagnet i. hearingan. energizing Winding each sideof the talking circuit when connection is Ina-die for conversation, and means actuated by said electromagnet to. interrupt a normal short- 4 circuit out; one-of said magnet windings and e to destsey the morniab substation control of ,said call v 21;. A -two=wire telephone system cormrising a telephone lineextendin two Emir-s from any substation to a cent-r otttce, a two-strand link-circuit forconnec- -conversction enter the connected line and link-circuit, a celsi signei normaikly MEHdGI the control of the subscriber; electromragnet having an energizing; in each.- limb ofithe telephones when connection is v for: eonwersatien, andmeazmseetna tied byseid electromagnet to interrupt a normalshont circuit abeut oneoifi-said magnet windings and to destroy the-normal slllbstetiomi eon- :0J1 .o -seid= cell signal; so 22;. .A two Wire. tekephone: sfyfsgtuemv coma: telephone. lineextendiimigr intwo Embsfrem at substation toe centrist .ofizee a two-strand linleeiitomit farms-king cermeetion sadsficn over the 1 Qonneetedline em]: Hansen:- cuit, an eleetnomsgnet lkfifl lllg' an weighting each-aisle of: the tfirlilfihlgifimbt wvhen connection is made-- fforeonversetion, means operative link-circuit to sa'i. te ener ize saa'kl ieleetromag-net, and entrant h -seisi-ieleetsomagnet to interrupt a no: -.s-ho-zt cim cuit about one said magnet windings; i

2 3.. A two-wire teleqohoniesystcm'comprisin a telephone extendi two Limbsiom msubsta ionte'm cent nmifiee a two-strand immune 1 tea making .eolwnees prising a. telephone line extendingm two teisaidr Line means for hot com-em" :tion= to; said line limbs -In.,ee:1as.-. for holdingon; the connection efi'said Winn to said line kmbs; for I versatio n over the connected lineandlinlcircuit; a 'call signa'l' hormallynriderthecon-j conversation over the connected line and link-circuit, an electromagnet havin -a-n'en ergizin winding ineach limb of-t e telephone inewhen connection is made for conversation, means operative upon'the connec tion of saidi-link circuit to said line to enerize said electromagnet, and means actuated by said electromagnet to interrupt a normal short circ'uit about one of said magnet windings.

24. A "two wire telephone system comrising a telephone line 'extendin in two limbs from a substation to a centra oflice, a two-strand link -circuit for makin connection to said line limbs, means for ho ding con.-

versation over the connected line and link circuit, a call-signal normally under the control-of the subscriber, an elctromagnet havin an energizing winding in'each side of the ta king circuit when connection is made for conversation, means operative upon the connection of said link-circui-t:to said line to energize said electromagnet, and means actuated by said electromagnet to interrupt a normal short-circuit about one of said magnet windin s.

25. twowire telephone system comprising a telephone line extendin in two imbs from a substation to a centra ofiice, a two-strand link-circuit for makin tion to saigl line limbs, means for-ho ding conversation-a-Tover the connected line and linkcircuit, a call signal normally under the control of the subscriber, an electromagnet hay-l in an'ene'rgizing winding in each limb of the te ephone line when connection is made for conversation, means operative -u onthe connection of said. link-circuit to said line to energize said electromagnet, and means aotuated by said-'electroinagnet tointelrupt a normal short circuit about one" of said magnet windings. 1

-2 6A two-*wir'e telephone system cone rising a teleplione line extendin imbs from a substation to-a "contra office; 'a vtwo strand'"link-circuit'for Ina-kin in two I x coiinection to said line limbs; means forho ding control- Of I the subscriber, 1 an eletromagl'net' havan: energizing winding in each side of the m ta iing circuitwhen connection is made for conversat-ionjmeans operativeupon theconnection of's aidlin'k circuit to said line to -en- 'ergize saideleetroni agnet; an d means actuated by said eleotromagnet to interrupt a normal short-circuit 1 about one E of sai d magnet and to 'dsstroy-the'inormal suhstatienroon rol flflffisaid call-"signal. -"i 27. A -"two-- i e" imbsi from 'asubs-tation to-acentral ofiice,

a -two'-straridzlink+eircuit I for making --oonconnec;

lay.

30. Atwo wire telephone system com tion to a source of current l ne signal normally responsive to-callmg curline, acut-oi relay,

t lephone-system comrising "a' telephone line ei'rtending in two ing said winding hiert to calling neutralizing winding asso-ciafl'led with :said u link-circuit,'-a call sign-al normally under the control of the subscriber, an electroma et having an energizing windingiiin each limb of the'telephone line when connection is made for conversation, means operative :upon the connection of' said link circuit to said line to energize said electromagnet, and means actuated by said electromagnet to interrupt a normal short-circuit about one of said magnet windings and 28: A two wire telephone system comprising a telephone line eX-tendin in two limbs from a substation to a contra ofiice, a battery, a line signal, a line relay connected only between one line limb and battery, a

to destroy the normal substation control ofs'aid call-signal.

cut-off relay having an energizing winding permanently included in thesame line limb, a two-strand link-circuit for making connection to said line limbs, and'mea'n-responsive to such connection to close a circuit through said relays in series.

2-9. A two wire telephone systen-i'oomprising a telephone line extending in two limbs from a substation-to a central office, a two-strand link-circuit formaki'ng connection to said line limbs, a grounded battery in bridge of said strands and having its grounded terminal connected to the tip strand, 'a line signaL-a. line relay connected between the tip limb of the line and the live pole-of said battery, a o-ut ofi-relay having an energizing winding included in the tip limb of the line, and a grounded-branch extend-- ing from the sleeve limb of the line-throughnormally closed contacts ofsaid cut-off reprising a telephone-line extending in two imbs from .asubstation to acentral oflice, a two-strand link-circuit for making conne tion to said line limbs, a-g-rounded battery in bridgeof said strands and having its grounded terminal. connected-to the tip "strand "a llfiE-Sifil, a line relay connected between thetip hot the line and the-live polel of: said I battery, a. cut ofij relay having an energizing-- winding included in the I limb of the line,- a grounded branch exten ing from the sleeve limbwof the -line through normally closed- .contacts of saidcut-.ofii relay, and supervisory relay windings included in said battery bridge. t 31'. A telephone exchange system comprising atelephoneline .exten mg firoma substaat the-exchange, a

rent in said 1-ine,'-a' terminal for the a winihng for said relay associated-with: that =p0rtion-1of the line ex tending to the substation, means for rendet- -current, a

Winding, a link-con ctor, .-meanswhereby the connection of said link-conductor with said switching terminal completes an energizing circuit for said relay, and switching mechanism actuated by said relay whenenergized to serially include said windings in differential relation in the talking circuit of said line, whereby the impedance of said windin s is neutralized.

32. telephone exchange system comprising a telephone line extending from a substation to a source of current at the exchange, a line signal normally responsive to calling current in said line, a switching terminal for the line, a cut-off relay, a winding for said relay included in that portion of the line extending to the substation, means for rendering said winding inert to calling current, a neutralizing winding associated with said winding, a link-conductor, means whereby the connection of said link-conductor with said switching terminal completes an energizing circuit f or said relay, and switching mechanism actuated by said relay when energized to serially include said windings in differential relation in the talking circuit of said line, whereby the impedence of said windings is neutralized.

33. A telephone exchange system comprising a telephone line extending from a substation to a source of current at the exchange, a line signal normally responsive to calling current in said line, a switching terminal for the line, a cut-off relay, a winding for said relay serially included in that portion of the line extending to the substation, means for rendering said winding inert to calling current, a neutralizing winding associated with said winding, a link-c0nductor, means whereby the connection of said link-conductor with said switching terminal completes an energizing circuit for said relay, and switching mechanism actuated by said relay when energized to serially include said windings in differential relation in the talking circuit of said line, whereby the impedance of said windings is neutralized.

34. A telephone exchange system comprising a telephone line connecting a substation with the exchange, a line signal normally under the control of the substation, a relay for destroying the substation control, a winding for said relay in a normally open circuit, a normally short-circuited Winding for said relay, means under the control of an operator for closing circuit through said first mentioned winding to destroy said substation control, and to bring said short-circuited winding into difierential relation with said first-mentioned winding, and means for maintaining an unequal flow of current in the two windings.

In Witness whereof, I hereunto subscribe my name this 11th day of January, A. D., 1906.

HARRY o. WEBSTER.

It is hereby certified that in Letters Patent No. 930,517, granted August 10, 1909,

upon the application of Harry G. Webster, of Chicago, Illinois, for an improvement in Telephone-Exchange Systems, errors appear in the printed specification requiring correction, as follows: In line 107, page 3, the reference-numeral 2' should read 3; line. 111, page 6, the compound word link-circuits should read link-circuit,

and line 85, page 8, the word mean should read means, and that the said Letters Patent should he read with these corrections therein that the same may conform to the record of the ease in the Patent Ofiice.

Signed and sealed this 5th day of October, A. D., 1909.

[SEAL] C. C. BILLINGS,

Acting Commissioner of Pain: is. 

